Psychology questions

• Research method


  A technique for gathering data on the mind and behaviour
• Experiment


  It involves an IV and a DV
• Independent variable (IV)


  The variable in an experiment which is changed or manipulated
• Dependent variable (DV)


  The variable in an experiment which is measured, to see how it has been affected by the IV
• Operationalise a variable


  To make it specific and measurable
• Extraneous variable


  Variables, other than the IV, which could have an effect on the DV
• Validity


  Whether we are measuring what we intended to measure
• Presence of extraneous variables


  Can reduce the validity of findings, as they mean the experimenter is no longer measuring what they intended (no longer just the affect of the IV on the DV)
• Situational variables


  Variables to do with the environment or situation
• Participant variables


  Variables to do with differences between participants
• Order effects


  Whereby the order in which participants complete the different conditions of an experiment influence how they behave (this includes gaining practise, becoming tired or bored)
• Demand characteristics


  When participants think they know the aim of the research and change their behaviour, acting in a way that they think the psychologist wants them to
• Investigator effects


  When the researcher unintentionally gives clues to participants about how they should behave, which then alters their behaviour
• Standardised procedure


  Where the procedure of a study is the same across all conditions, and for all participants
• Counterbalancing


  Where half of the participant group experience condition A then condition B, while the other half experience condition B then condition A
• Randomisation


  When participants are randomly assigned to condition A or B as their first or second test condition
• Single-blind technique


  When information about the study is withheld from participants (to prevent demand characteristics)
• Double-blind technique


  When the aims of the study are withheld from both participants and researchers (also prevents investigator effects)
• Hypothesis

  A statement of predicted outcomes based on a theory being tested
• Null hypothesis


  A prediction that the result or outcome will find no effect or very little effect
• Alternative hypothesis


  A prediction that the result or outcome will find a significant effect. It is known as an alternative hypothesis because it is 'alternative' to the null hypothesis
• Null hypothesis for investigating whether age affects short-term memory


  • There will be no significant difference in the short-term memory ability (measured through their score on a digit span test) between older participants and younger participants. Any difference will be due to chance
• Alternative hypothesis for investigating whether sweets have an impact on children's attention span


  • There will be a significant difference in the attention span (measured through time spent concentrating in a lesson) between children who it lots of sweets and children who eat few sweets
• Target population


  The group of people being investigated, to which the findings will be generalised
• Sample


  A selection of the target population that is directly studied in an investigation
• Participants


  The people who take part in a study
• Representative sample


  Whether results of a study represent the whole population, not just the sample used
• Generalisable findings


  Extent to which results can be generalised to groups of people other than the sample
• Random sampling


  Every member of the target population has equal chance of being selected
• Strengths and weaknesses of random sampling

  • Strength: free from researcher bias - researcher has no influence on who is chose
  • Weakness: difficult / costly to ensure every member of target population has equal chance of being selected
• Stratified sampling


  Subgroups are identified within the target population. Participants are obtained from each subgroup, using a random sampling method, in proportion to their occurrence in the target population
• Strengths and weaknesses of stratified sampling

  • Strength: sample is likely to be representative as each subgroup within the target population will be represented
  • Weakness: difficult / costly to ensure all subgroups in the target population are represented in the sample
• Volunteer sampling


  Participants who are willing to volunteer themselves to take part in a study (often means advertising the study)
• Strengths and weaknesses of volunteer sampling

  • Strength: minimal effort from researchers – quicker and easier than other methods
  • Weakness: unlikely to produce a representative sample – not everyone will see the advert or want to respond
• Opportunity sampling


  Selecting anyone who is available and willing to take part at the time
• Strengths and weaknesses of opportunity sampling

  • Strength: requires little effort from the researcher (so likely to be the cheapest method)
  • Weakness: biased sample likely to be produced, as not every member of the target population may be around at the time of the study
• Experimental design


  Refers to how participants are organised or allocated into the different conditions of a study
• Independent groups design


  Involves multiple separate groups of participants completing only one condition of a study
• Repeated measures design


  Involves the same participants completing both / all conditions of a study
• Matched pairs design


  Involves two separate groups of participants completing only one condition of a study, yet these groups are matched on important characteristics, such as age or gender